With respect to electronic devices including organic EL devices, heretofore, in general, a film that contains a material for making those devices function has been formed according to a vapor deposition method. On the other hand, it is also investigated to form a film according to a coating method, but it is in a situation in which a material sufficiently suitable for a coating liquid could not as yet been realized, and a development of a polymer material having not only charge transporting properties but also solubility is now under way.
As a material for organic EL devices, polyvinyl carbazole (hereinafter abbreviated to PVK in some cases) has been known through the ages (see PTL 1, page 2, right upper column), and along with the development of organic EL devices, a development of PVK is also under way. PTL 2 describes an organic EL device using a polymer produced through copolymerization of a vinylanthracene derivative and a vinylcarbazole derivative, in which, however, a polymer form having an increased molecular weight is not produced.
PTL 3 discloses a copolymer comprising a unit having a carbazole derivative and a unit having an amino group, in which, however, a polymer form having an increased molecular weight is not produced.